Antivibration boat construction



May 28, 1935. a. E. BALDUF I 2,002,517

ANTIVIBRATION BOAT CONSTRUCTION Filed June 20, 1951 4 Sheets-Sheet 1 (5 Z 5 O D l 1:- L 5% mg PFRCtlR m E .8 n g} I; E .6 4 g? 5 E 2 (b) m (c) & (d).

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INVENTOR o L BRUNO E. BAL. u

6o '10 80 a0 BY LOAD Pee Cup. L65.

ATTORNEY May 28, 1935; B. E. BALDUF ANTIVIBRATION BOAT CONSTRUCTION Filed June 20, 1-931 4 Sheets-Sheet 5 May 28, 1935.

B. E. BALDUF ANTIVIBRATION BOAT CONSTRUCTION FiledJune 20, 1931 4 Sheets-Sheet 4 INVENTOR BRUNO E Bm. DUF. .AT'TORNEY;

50 Fig. 8 is a sectional elevation through the re- Iiatented M gccasrz I ANTIVIBRATION BOAT CONSTRUCTION 'Bruno E. Balduf, Chicago, 111., assignor to United States Gypsum Company, Chicago, Ill., a corporation of Illinois Application June 2e, iesi, Serial No. states 6 Claims. (oi. lie- 36) This invention relates to the construction of Fig. 11 is a plan view of the resilient base taken boats of the type such as that employing motors on line ll -l i of Fig. 8. or engines for screw propeller actuation, and has The resilient clip as described in my aforereference more particularly to a boat construcmentioned co-pending application, comprises a 5 tion in which the movingparts, such as the central saddle member it which has opposite, or

motor and the thrust bearing on the propeller upwardly sloping arms i6 formed at the upper shaft are resiliently connected to theboat frame end into resilient loops il. Downwardly extendin order to eliminate vibration of said frame. ing legs it are formed on the loops ill and these In my co-pending application, Serial No. legs'terminate in clip ends i9 which preferably 1 340,121 filed February 15, 1929, to issue as Patextend outwardly in a plane difierent from but ill ent No. 1,811,250 on Junev 23, 1931, of which this parallel to the saddle member 55. application is a continuation'in part, I have The saddle member l may be secured by described a spring clip especially effective in spot-welding, riveting or the like, to a tubular sound reducing construction. I now find that rib 2B which is preferably rectangular in crossthis general type of spring clip canbe used to section and is of sufiicient thickness so that a is advantage in marine construction for eliminatsupporting plate 21 secured to the upper suring the vibration of the boat frame due to the face of said rib, is spaced apart a sumcient dismoving parts; tance above the loops ii to allow the free deflec- Reference is to be had to the accompanying tion thereof. The clip ends it are secured to a drawings forming a part of this specification, in rigid channel base frame 22 by spot-welding or go which the like, so as to form a strong foundation for Fig. l and 1A are graphical charts showing suppflrting the motor 0f the The frame experimental curves derived by dynamical meth 22 m y a so l de a lower frame angle 1781i ods showing the relation of the amplitude ratio 23 which is d d to t frame 22 d o p 25 of 20 gauge spring clips to the frequency of the a therewith to make a rigid fionstluction- 25 disturbing force and the load carried by each The plat 25 i p a y r an ular in shape clip, and is provided with peripheral stiffening angle Fig. 2 is a graphical chart showing an experiflanges Zia. and bolt holes it so that the motor mental curve derived by static methods showcan be securely bolted to said plate 2 l A central ing the relation between the load on a 20 gauge rectangular Op ni 25 is pr vi I he Pl 30) spring clip and deflection together with a curve 2| to give clearance for the cranlz-case of the determined mathematically showing the relation motor 6- MOSt of the spring Clip extend In between the load on the spring and its natural a series along each. the -f members frequency. and angle bars 23, said clips be ng turned ed 35 Fig. 2A is a graphical chart showing load de- Wise t axis of the Propeller Shift to be 35 flection curves on a 20 gauge two leaf spring es ribed, so as to give lateral sta l y and clip and each of its leaves, obtained by static rigidity i n l i n m & hoYlZOntal P g as, but still permit vertical movement of the motor Fig. 3 is a sectional elevation of a boat em- F end ql y be 4Q my improved anti-friction device, desired, Said 811d chps being turned at light .40

. Fig. 4 is a plan view of a resilient base for angles to the clips along the sides, t E i/ supporting the motor or engine of a boat, ri idity in both horizontal directions.

Fig. 5 is a sectional elevation through the re- I e found that themam slmng 01195 1 ates at the highest efficiency from a sound and silient devices forming a art of the motor base taken on line t-'-5 of Figgi, vibration insulating standpoint, when they are ticular and rather limited Fig. 6 i" a sectional elevation through the loaded with a par motor has; taken on line 5-6 of Fig. 5, range of loading. 1, therefore, find 1t desirable Fig. 7 is a sectional elevation through the dein many1 instamgzisi tfion 3113c? a 11;? 0158x2052; 'ces associated with the rop'eller shaft, spring c 1p in a v1 p by the weight of the motor. For this purpose silient thrust bearing used on the propeller shaft, of auxiliary loading, 1 utilize auxiliary spring Fig. 9 is a sectional elevation taken on line clips 21 of the same general shape as the main 9-9 of Fig. 8, spring clips. The auxiliary chp 21 has a saddle Fig. 10 is an elevation taken on line [IL-l0 of member 28 through which passes a set bolt 29. Fit. 8, v A washer 30 is pl ced on top of the saddle member 28, and a nut 3i is threaded onto the set bolt 29 above said washer. The lower part of the set bolt 29 is threaded to engage an internally threaded bushing 32 which is preferably welded between the plates 22 and 23. The auxiliary spring clip 27 has its outstanding ends resting upon a connecting plate 34 which in turn rests upon the plate 2i, tap bolts 35 serving to securely attach the clip ends and plate 34 to the plate 2|. Micrometer indicator marks 36 are provided on the shank of the bolt 29 at about the level of the plate 34 so that when the nut 3! is tightened down, the amount of deflection of the main spring clips can be accurately determined by the number of said micrometer marks 36 extending above the top surface of the plate 36. A cover 38 is preferably secured above each of the auxiliary spring clips 2i by means of bolts 39, so that said cover prevents dirt and liquids from getting in around the spring clips, but yet is readily removable for changing the adjustment of the auxiliary spring clip M. A material 38a of low density, such as fibrous material impregnated with oil or asphalt, is preferably put in the space around the main spring clips to reduce drum action and prevent deterioration of metal parts.

In some cases where the center of gravity of the motor 26 is comparatively high above its base, it is desirable to have a means of locking down the motor in position to prevent any deflection of the clips, whenever the necessity arises, as in making repairs, etc. For this reason I may provide an annular flange or shoulder 4| on the bolt 29 intermediate plate 2;! and bushing 32, said flange preferably having a lead washer 42 on its upper surface to contact with the lower face of the plate 2! when nut 3! is tightened down to a considerable extent. When said nut is tightened down completely, the main spring clips are deflected totheir maximum extent and the bottom of plate M will rest on the lead washer 33 to give a solid base for the motor.

One of the principal sources of vibration in a boat is due to the vibrating and thrusting action of the propeller shaft upon the boat frame. In order to overcome this source of vibration, I provide a thrust bearing on the propeller shaft which is resiliently attached to the framework of the boat by my improved spring clips. The propeller shaft 42 upon which the thrust bearing is mounted, is provided with a propeller 43 and is supported by a bearing hanger dd secured to the frame of the boat 35. The shaft 52 passes into the boat at a slight inclination to the horizontal through a stuffing box it of usual design. The inner end of the shaft 52 is provided with a flexible coupling comprising an annular flange til rigidly ireyed or otherwise secured to the end of said shaft 6?. Near the outer periphery of the flange it, a plurality of annular holes til are formed in said flange with the axes of said holes extending parallel to the axis of the shaft 52. A companion flange 49 is secured by means of bolts at to a flanged sleeve 58 which is secured by nut 52 and a suitable key to the end of a shaft 53 leading to the crankshaft of the motor. A plurality of holes 54 are provided in the flange it to register with the holes 48. The two flanges 41 and 49 are spaced apart to form a clearance space55 for permitting slight axial movement of shaft 42 relative to shaft 53 under the action of my resilient thrust bearing to be hereinafter described. A' pin 56 of laminated steel, passes through each of the holes 48 and W, said pins being provided with a groove 51 at one end to receive an annular snap ring 58 for retaining said pins in position. Due to the laminated character of the pins 56, said laminations will deflect slightly when the load of the motor is applied to the shaft 32 and allow a slight rotary movement of the flange 49 relative to the flange 41, thus overcoming the vibration of starting and stopping.

The thrust bearing proper consists of a sleeve 60 which is shrunk in place on the shaft 32 and secured thereto by means of dowel pins. One end of said sleeve 60 is threaded to receive a nut 6| and the other end of said sleeve is provided with an annular shoulder 62. A pair of ball races 63 are shrunk upon the outside of the sleeve 50 and secured firmly together between the nut 5i and shoulder 62. A pair of annular companion ball races 6 are provided with balls 65 so that said balls are free to roll between ball races t3 and 64. The ball races 6 are pressed in place and secured in an annular housing casting 66 having outstanding flanges til on its lower side, which are secured by bolts 68 to a base plate 69. Housing covers 16 are secured to the housing bracket 66 by means of bolts ll, said covers having central openings adapted to loosely fit the shaft 62.

The base plate 69 has downwardly extending stiffening flanges 13 formed around its outer periphery, and tubular ribs 14 are secured to the lower side of the plate 69, as by rivets it. Each of the ribs- 14 rest on the saddle member I6 of a multiple leaf spring clip composed of two or more superimposed spring clips, such as those shown in Fig. 9. The outstanding clip ends ll, are secured to a U-shaped bracket 18 which in turn is secured by bolts 19 to a channel member or other suitable structural shapes, the latter being rigidly secured to the framework of the boat. The advantage of using the multiple leaf spring clip is that a comparatively heavy load can be carried with but a few spring clips. These multiple leaf spring clips have different radii on their resilient loops it so that said loops are spaced apart and act independently one from the other. The smaller the radius of these loops, the less resilient the spring will be and therefore, the natural frequency of the different leaves of the spring will vary and the composite result can be adjusted to any predetermined extent by the proper selection of gauge of metal and radius of the loops.

The U-shaped bracket 18 has a pair of upstanding legs 83 which are provided with slots M for removably receiving the shaft 92. A plurality of multiple leaf spring clips 85 have their ends secured to the inside faces of the bracket legs 83, and friction blocks 88 are secured to their saddle members Bl. An arcuate ring as is provided with U-shaped rigid clips 89 which are secured by bolts 90 to each of the cover plates It. Each of the rings 88 contact with the blocks 8% and serve to deflect the spring clips 85 when the shaft 42 is vibrated axially due to the rotation and thrust of the propeller. Since the spring clips 85 are arranged on both sides of the thrust bearing, the vibration of the propeller shaft will be absorbed by said spring clips whether the boat is going forward or is in reverse. As seen in Fig. 9, the spring clips 85 are preferably arranged around a semi-circle deflected in a vertical direction.

In operation, the vibration of the motor 26 is taken up by the spring clip positioned under the ribs Zll, and a load in addition to the weight of the motor 26 is placed on said main spring clips by means of the auxiliary clips 21. The load on the main spring clips is adjusted by rotating the nut 3! on bolt 29. During an emergency, such as making repairs, etc., the nut 39 may be screwed down completely so that the bottom of plate 2i rests rigidly upon the lead washer 33, thus putting the main spring out of operation. The vibration of the propeller shaft 42 is taken up by the ball bearing thrust bearing shown in Figs. 5 and 8, which transmits the thrust of the shaft through rings 88 onto blocks dfi and spring clips 8i, which are sup-' ported by legs 83 of the U-shaped bracket "ill.

Vertical vibration of the thrust bearing is taken up by the spring clips to. Slight axial movement of shaft G2 due to deflection of the spring clip 81 is permitted, due to the clearance space 55 between the flexible coupling flanges ti and as. Laminated pins 56 loosely connect said flanges H and 9 to permit a yielding rotating movement of one flange relative to the other flange.

It should be understood that much the same principles as herein described can be applied to resiliently support other machinery carried by a boat, such as pumps, compressors, refrigerating machinery, etc.

I would state in conclusion that while the illustrated examples constitute a practical embodiment of my invention, I do not wish to limit myself precisely to these details, since. manifestly, the same may be considerably varied without departing from the spirit of the invention as defined in the appended claims.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. In a resilient construction for boats, a motor supporting element, a plurality of flat spring clips secured to said element, said clips being also secured to the frame of said boat and being arranged to reduce the transmission of vibration from said motor to said boat frame, and a material of low density in the space around said spring clips.

2. In a resilient construction for boats, a rigid boat frame, a vibrating part, and spring clips having portions thereof secured to said frame and part, said clips comprising a plurality of superimposed, independently acting leaves and integral loops, said leaves and loops being in face to face abutting relation near the center thereof but being out of contact one with another for a substantial distance.

3. In a resilient construction for boats, a boat frame, a propeller shaft, means for rotating said shaft, a thrust bearing supporting said shaft on said frame, and a plurality of spring clips having central saddle sections and integral loops, said clips being interposed between said thrust bearing and said frame so as to reduce the transmission of vibration from said shaft to said frame.

4. In a resilient construction for boats, a boat frame, a propeller shaft, means for rotating said shaft, a thrust bearing supporting said shaft on said frame, and a plurality of multiple, leaf spring clips interposed between said thrust hearing and said frame, said leaves having integral, independently, acting loops and being adapted to reduce the transmission of vibration from said shaft to said frame.

5. In a resilient construction for boats, a boat frame, a propeller shaft, means for rotating said shaft, a thrust bearing supporting said shaft on said frame, and resilient, flat, spring clips associated with said thrust bearing for permitting vertical movement of said shaft relative to said boat frame.

6. In a resilient construction for boats, a boat frame, a propeller shaft, means for rotatingsaid shaft, a thrust bearing supporting said shaft on said frame, and resilient, flat, spring clips associated with said thrust bearing for permitting both vertical and axial movementof said shaft relative to said frame.

BRUNO E. BALDUF. 

